log.fivesevenfive.orghttp://log.fivesevenfive.org
home away from homeen-ushttp://blogs.law.harvard.edu/tech/rssh4x0r(blaggy) 2.0pg@fivesevenfive.org (Phil Genera)60Sun, 12 Jan 2014 22:48:59 +0000
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIRCxIEUG9zdBiAgICAgICACgw
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIRCxIEUG9zdBiAgICAgICACgw
Sun, 12 Jan 2014 22:48:59 +0000
Google+ a little bit, but its mostly deeply embarrassing. Facebook is "disabled" unless I'm snowed in or in tech, so I'm basically an electronic hermit. Between that and the ham radios, I'm basically extremely old. I am surprised how much unhappiness facebook breeds; it makes me feel less alone but its

I'm in tech for Silent Sky at TheatreWorks, which I imagine is going to be my last professional gig; they've always been difficult to schedule and are now making me feel old rather than happy, as the crew remains the same age and I keep getting older. That said, I can't think of anyone else who still has such a complicated and time consuming hobby. Ah well.

Maybe I'll post a lot this week, even if I'm just shouting into the void. Its going to be a slow tech.

Comment on this
]]>
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBjKsQkM
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBjKsQkM
Wed, 16 Nov 2011 18:22:09 +0000By the by, if you have more data than will fit in a single RDBMS and you're not looking at Google's BigQuery right now, you really should be. It is amazingly hot shit.

Comment on this
]]>
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBj5oQkM
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBj5oQkM
Fri, 29 Apr 2011 20:45:05 +0000First, the CA DMV. In California, you can get a DMV appointment, which means you only wait half an hour to get your essential government service, instead of an hour and a half. Awesome, right? Except the next appointment is usually a month away. I've always been a good citizen, making my appointments, waiting patiently, and getting my registration done a few weeks after the legal deadline (10 days for used vehicle purchases).

Here's the thing though - if you seem like you know what you're doing, you don't have to prove you have an appointment. So you can go to the DMV whenever you want, stand in the appointments only line, and say you have an appointment for whatever the upcoming even-10-minutes time is, and bob's your uncle. If you seem confused or don't speak english, they'll want to see a printout of your appointment confirmation email, which is also easily faked. I'm not sure why I didn't think of this before. Proceed at your own risk, of course.

My second errand today was to get some keys copied. There's a great key show down the street from my house, so I stopped off on my way home from the DMV and asked if he could copy the key for my truck. This is an early chipped key, so there's a bit of RFID happening and you have to 'program' the vehicle to recognize the key. Normally this is done by using two already-working keys, and talking to the ECU by doing things with the keyless entry keypad. If you don't have two working keys (as I didn't), you have to connect a programmer to the OBD-II port and instruct the ECU to look for a new key. And before the ECU will do anything, a 10 minute timer has to expire.

I thought this was really weird at first - two keys to program it? 10 minutes to read a value and store it in NVRAM? What the what? - but its actually a pretty decent design. If you could program new keys with just one key, valets could readily steal cars. If all you needed was to talk to the ECU for a few seconds to program a new key, anyone with a key impression and some minor electronics knowledge could make off with the car handily. The delay helps out as much as is probably reasonable. Of course, none of this addresses the (probably super trivial) walk-by cloning that's possible today, but hey, it was almost 20 years ago when this stuff was designed.

Comment on this
]]>
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBiRmgkM
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBiRmgkM
Fri, 15 Apr 2011 23:37:55 +0000
I haven't left yet for the mission trip. I don't know why y'all think I have, but I haven't.

Of course, by the time you read this, I will have. So there; you don't have any more information than you did before.

Comment on this
]]>
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBiBzAgM
http://log.fivesevenfive.org/details?id=agtzfnBhbnRzLWhyZHIMCxIEUG9zdBiBzAgM
Mon, 13 Dec 2010 23:49:02 +0000
marvell open-rd client, to be specific). The reshape caused the overall storage capacity to go from ~1.2TB to ~2.1TB. I added the discs, started the reshape, and went to bed.

A few hours later, something stupid happened to the electricity in my garage and all my stuff got turned off. I fixed that, got everything turned back on, and went to check on the reshape. The kernel was complaining that the reshape wasn't far enough along to be automatically restarted, which was scary and seemed untrue. I emailed the linux-raid mailing list and talked to the maintainer a bit, and he seemed to think it was an overflow on arm specifically of the kernel code that performs this check.

Neil was right; when I eventually got a sufficiently modern version of mdadm running on an x86 machine, I was able to re-assemble the array and get it reshaping again. A few false starts later (I may have slightly unplugged the disks from the laptop while checking on it last night), the reshape completed successfully, I reattached the disks to the arm machine, and was able to extend the underlying ext4 partition without error. I've verified all the (important) data against checksums and backups, and there appears to be no lasting damage.

While this failure was due to the overall complexity of my storage system, it highlights the advantages of linux software raid: I was able to trivially move the disks to another machine to perform recovery and work around hardware-specific bugs.